As promised, one Rosewood resident didn't make it to the end of the line alive during last night's "Pretty Little Liars" Halloween special, set on a speeding locomotive. But the deceased did drop one doozy of a secret before meeting his demise.

The episode opened on Mona (a.k.a. A) in her room in Radley, ominously humming "Teddy Bears' Picnic" while painting a garish face onto a paper-mache mask. Clearly, Mona was not going to let the Halloween train leave the station without her... or her hoodied-helper, whom she passed a handful of pills and bullets!

Meanwhile, Spencer came home to find an unwanted surprise in her kitchen—Garrett Reynolds, who had some intel for her. But Toby interrupted, demanding Garrett leave. "You make it so hard to be a modern post-feminist when you're such an alpha male," Spencer waxed before pulling a copy of Ms. magazine out of her backpack. Or not.

Spencer had a date for the monster mash, but Hanna and Aria weren't so lucky. Caleb was still healing from his injuries from the mid-season finale, while Ezra had a last-minute job interview in Philadelphia about ghosting (heh! Halloween pun!) a biography. No matter, us modern post-feminists can attend a party without a man on our arm...

And show up they did, in fine fashion, channeling famous women in cinema: Hanna as Marilyn Monroe, Aria as Daisy Buchanan from "The Great Gatsby," Emily as Barbarella and Spencer as Lauren Bacall. Of course, the other usual suspects were aboard too, including Jenna, Noel (great choking gag, guy! NOT!) and Jason. Oh, and plenty of masked, could-be menacers.

Though a number of the costumed cabal ended up being friend rather than foe. Caleb snuck onto the train under the guise of the Phantom of the Opera, while Garrett hid behind a creepy doll mask so he could pull Spencer aside to reveal his secret. Namely, that though Jenna thinks he killed Alison, he didn't. In fact, the last person he saw with Alison the night of her murder was...Aria's dad!

Speaking of Aria, Spencer told Garrett to stay put while she tracked her friend down, but Aria was no where to be found! Following guest star Adam Lambert's set, Creepy Porcelain Jester slipped something into Aria's drink, and she woke up bound, gagged and in a box. And she wasn't alone. Garrett's dead body was in the box too! Which gave us all the creeps!

As the girls searched the train for Aria, they only found more trouble. Creepy Porcelain Jester tried to throw Spencer from the train (though Paige totally handled him/her!) and a Caleb imposter got a little too close to Hanna. While Aria struggled to free herself, she could hear a guy's and a girl's voice (Mona and Toby?) as they attempted to foist the box off the train, but the pretty little liars found Aria just in time to prevent her from becoming missing cargo...

...Which is a perfect transition to discuss another item found on the train: AN ADDITIONAL BODY. Hiding in a coffin pulling double-duty as a drinks cooler was a body bag, which we can probably assume was holding Alison's remains. Worst. Party. Favor. Ever.

Also of note was the bizarre sideplot occurring at Hanna's home. Her mom welcomed what seemed to be a little girl ghost into their house. Is "Pretty Little Liars" taking a turn for the supernatural? We'll have to wait and see when the series returns for the back half of season three in 2013!

What did you think of last night's Halloween special? How do you think ghost girl will factor in? Are you convinced Alison is in the body bag? Do you think Aria's dad had something to do with Alison's murder? (Perhaps that's why they really moved to Iceland?) Tell us all your thoughts and theories in the comments and on Twitter!